JP3306892B2 - Semiconductor optical integrated device and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor optical integrated device and a method of manufacturing the same, and more particularly, to a semiconductor optical integrated device suitable for use in an optical communication module and an optical communication system and a method of manufacturing the same.

[0002]

2. Description of the Related Art By introducing a superlattice structure having a biaxial strain, a semiconductor laser, an optical modulator, an optical switch, a photodetector,
It is known that characteristics of a semiconductor optical functional device such as an optical amplifier can be greatly improved. In the future, it is thought that these monolithic integrations will be indispensable with the progress of optical application technology, but it is impossible to integrate superlattice structures with different strains with the current crystal growth technology, and realization examples Was not there. For this reason, the polarization of the operating light in the integrated device has been limited to the TE mode.

On the other hand, as a method of integrating heterogeneous functional elements on the same semiconductor substrate, as shown in FIGS. 1A and 1B, a method of controlling band gap energy in a substrate surface using selective growth has been proposed. ing. In addition, as related to this type of semiconductor optical integrated device, for example, the IEICE Autumn Conference C-133, September 5, 1991, may be mentioned.

[0004]

However, according to the conventional method, the quantum well structure 3 is grown on the semiconductor substrate 2 on which the insulating mask 1 is formed by crystal growth, so that the quantum well layers have different thicknesses in the substrate plane. In addition, quantum well optical waveguides having different quantum levels can be integrated by single crystal growth. In this case, the thickness of the quantum well layer and the mixed crystal composition of the integrated device are uniquely determined from the required insulating mask width. For this reason,
It is difficult to control the amount of strain in the plane of the substrate, and it is difficult to apply a strain-based quantum well structure that can be expected to further improve device characteristics. Therefore, it has not been possible to optimally design an element structure such as a quantum well layer for each integrated element. An object of the present invention is to significantly improve the performance of a semiconductor optical device by integrating quantum well structures having different strain amounts (degree of lattice mismatch, compressive strain / tensile strain). It is a further object of the present invention to provide a quantum well structure in which the amount of strain (lattice mismatch, compressive strain / tensile strain) differs in the plane of the substrate. In addition, by combining the above-described distortion amounts, integration of optical waveguides having different polarization plane dependences of optical characteristics which did not exist conventionally, and an optical integrated element capable of arbitrary control of the polarization plane of operation light, and its preferable manufacturing Provide the law.

[0005]

In order to achieve the above object, the present inventors provide a semiconductor optical integrated device in which the composition of the quantum well crystal layer, that is, the amount of lattice mismatch with the underlying substrate is different. Further, a method of manufacturing a semiconductor optical integrated device for realizing the above is provided by a region selective growth technique using an insulating film patterning mask formed on a semiconductor substrate.

[0006]

First, the features of a semiconductor optical integrated device having a quantum well structure in which the amount of lattice mismatch differs in the optical axis direction will be listed.

(1) When a quantum well waveguide layer having a compressive strain and a quantum well waveguide layer having a tensile strain are integrated, light having a polarization plane parallel to the crystal growth plane (TE polarization) in the compressive strain quantum well element is obtained. In the tensile strained quantum well device, light having a plane of polarization perpendicular to the crystal growth surface (TM polarized light) can be controlled independently, so that polarization independent optical devices and arbitrary polarization plane control of operating light can be controlled. It is possible to realize an optical integrated device capable of performing the above.

(2) When a quantum well waveguide layer having a compressive strain is used as a semiconductor active device and a quantum well waveguide layer having a tensile strain is used as a semiconductor passive device, TE polarized light generated from the compressive strain quantum well active device is used. On the other hand, the propagation loss of the tensile-strain passive waveguide layer can be greatly reduced. This is because light absorption of TM polarized light becomes dominant in a semiconductor layer having a tensile strain because light hole bands are involved in light absorption.

It should be noted that a similar argument holds when a quantum well waveguide layer having a compressive strain is used as a semiconductor passive element and a quantum well waveguide layer having a tensile strain is used as a semiconductor active element.

(3) When a quantum well waveguide layer having a tensile strain is introduced into both active and passive elements, light hole bands are all involved in optical characteristics such as light emission, light absorption, and change in refractive index, and operation is performed. The light becomes TM polarized light. Therefore, for the light emitting element, it is possible to improve the luminous efficiency, the stability of the oscillation wavelength and the temperature characteristics, the high-speed operation, and the like. For a passive element, an increase in an absorption coefficient or a change in a refractive index, an increase in operation speed, and an increase in an operation light output can be realized. (4) When a quantum well waveguide layer having compressive strain is introduced into both active and passive elements, the effective mass of heavy holes is reduced to about 1/10, and an effect similar to that of light holes appears.
Therefore, an improvement in element performance similar to that of (3) can be expected.

As described above, a high-performance optical integrated device can be realized by a combination of optical integrated devices having quantum well structures with different strain amounts.

In the following, the amount of distortion (degree of lattice mismatch, compressive strain /
A method for manufacturing a semiconductor optical integrated device having a quantum well structure having different tensile strains will be described. An insulating film patterning mask 1 is formed on a semiconductor substrate 2 shown in FIG. Here, a portion where the semiconductor is exposed during patterning is defined as a growth region, and the width thereof is defined as a growth region width. As shown in FIG. 2, the insulating film mask 1 is patterned so that the growth region width changes in the optical axis direction. As shown in FIG. 3A, on a semiconductor substrate 2 having such an insulating film patterning mask 1, an optical waveguide layer 4, a quantum well layer 5, and a quantum barrier layer 6 composed of a III / V mixed crystal semiconductor are formed. The quantum well structure 3 and the cladding layer 7 to be formed are vapor-phase grown. here,
The quantum well layer 5 is composed of two or more group III elements having different lattice constants, for example, Ga and In. In this case, since crystal growth does not occur on the insulating film patterning mask, growth occurs selectively only in the growth region (region selective growth). In addition, since the growth source species that has flown onto the insulating film patterning mask 1 undergoes surface diffusion and vapor phase diffusion in the growth region, the growth rate increases as the opening length becomes smaller. At this time, the composition of the growth layer also changes. This is a phenomenon that occurs because the diffusion length on the insulating film patterning mask 1 is different between homologous element materials, especially between group III materials. For example, in the case of Ga and In described above, since the diffusion length of the In source material is larger, the In composition in the crystal is enriched by selective growth, and the crystal lattice constant is longer than that of the underlying substrate. Since the magnitude relationship between the diffusion length and the lattice constant differs depending on the combination of the group III elements, it is additionally noted that the crystal lattice constant may be shorter than that of the base substrate due to the selective region growth. Further, the increase in the thickness of the grown layer and the change in the composition become remarkable as the width of the grown region decreases. Therefore, if this composition change is positively used, the composition of the quantum well structure in the substrate surface, that is, the amount of strain can be easily controlled by the growth region width. High performance semiconductor optical integrated devices having different quantum well structures can be manufactured. Specifically, in the crystal growth of the quantum well structure shown in FIG. 3A, as shown in FIG. 3B, in the region b having a large growth region width, the crystal lattice constant of the quantum well layer 5 is changed to the quantum barrier layer 6.
Is set in advance to be shorter than that of the above, to obtain a quantum well structure having a tensile strain in the quantum well layer. At this time, a quantum well structure having a compressive strain in the quantum well layer is automatically formed in the region a having a small opening length due to the composition change described above. Here, since the group III element composition ratio is 1 or a sufficiently large mixed crystal semiconductor is used for the optical waveguide layer 4, the quantum barrier layer 6, and the cladding layer 7 as shown in the examples later, as shown in FIG. No significant difference occurs in the composition of the growth layer between the two regions a and b. For example, in In _x Ga _1-x AsP, when the composition ratios of In and Ga, which are group III elements, are both about 0.5, the change in layer thickness and composition in two regions is large. This change decreases as the composition ratio increases. The degree to which such a composition ratio of the compound semiconductor contributes to the change in the layer thickness and the composition in the selective region growth is much larger for the group III element than for the group V element. Assuming that the composition ratio of the homologous elements A and B is [A] and [B], respectively, the value of {defined by [A] / [B]} is 0.2
A large change is obtained when 5 ≦ χ ≦ 4, and a maximum change is obtained when 1 ≦ 1. At this time, the growth condition is such that the lattice constant of the quantum well layer in the region b having a large aperture length and the gas composition and the moving distance of the atoms constituting the mixed crystal semiconductor crystal on the insulating film patterning mask 1 differ among the elements. Therefore, the quantum well structure 3 in which the composition and the thickness of the growth layer are different according to the patterning width is automatically formed. Since the regions a and b are formed by the same crystal growth, the two regions are extremely smoothly coupled, the coupling loss is significantly reduced, and the optical coupling efficiency is approximately 10%.
0%. FIG. 4 shows that the growth conditions such as the source gas supply amount and the growth temperature are kept constant, and the InGaAsP quaternary layer and the InGa
5 is an example of the result of examining the degree of lattice mismatch between the growth layer and the underlying substrate with respect to the patterning mask width when the As ternary layer is formed by metalorganic chemical vapor deposition on the InP substrate. As for the crystal growth, as shown in the illustration in the figure, the entire growth region width is 20 μm.
The conditions were set such that the mask width was zero, that is, the lattice irregularity was negative in the case of the mask width of zero, that is, the normal growth, and that the lattice matching was performed in the case of the mask width of 50 μm. As shown in the figure, by setting different mask widths on the same substrate, a plurality of types of quantum well structures having different strain amounts can be arbitrarily set. FIG. 5 is an example of a result in which the equivalent energy gap change of the quantum well structure due to the increase in the quantum well layer thickness and the change in the well layer composition described above is represented by the PL peak wavelength. In the conventional method, the energy gap control width is limited to about 100 meV because only the energy-gap reduction effect due to the compressive strain is used. It can be expanded to about twice the conventional size. For this reason, the degree of freedom in designing the present technology for application to an optical integrated device is greatly improved.

[0013]

Embodiments of the present invention will be described below with reference to FIGS.

Embodiment 1 In FIG. 6, the region (growth region width) where the semiconductor substrate is exposed on the n-InP substrate 8 is in the direction of the optical waveguide between the region where the diffraction grating 9 is formed and the region where the diffraction grating 9 is not formed. An insulating patterning mask 10 such as SiO ₂ , SiN _x , a-Si or the like is formed. _{Next, In 0. 85 Ga 0.} 15 As 0. 33 P 0. 67 four yuan waveguide layer _{11, In x Ga 1-x} As ternary quantum well layer 12 and the In ₀ in the patterning on the substrate.
_{85 Ga 0. 15 As 0.} 33 P 0. 67 consists of four yuan quantum barrier layer 13 multiple quantum well structure 14, and sequentially the p-InP cladding layer 15 is crystal grown by metalorganic vapor phase epitaxy. From FIG. 4, the opening lengths of the two regions are 45 μm and 60 μm, respectively.
, The gain peak wavelengths are each set to 1.4.
At the same time, the lattice strains of the quantum well structure are set to -0.5% and + 0.5%, respectively. After forming each semiconductor layer in this manner, the upper electrode 16 and the lower electrode 17 are formed by a normal vapor deposition method or the like to obtain a semiconductor optical integrated device. This structure is an optical modulator,
By using as a distributed feedback laser, an electro-absorption modulator integrated light source can be realized. FIG. 7 shows an element structure of an embodiment in which a buried structure and a current confinement structure are further introduced by a known method. By introducing tensile strain into the modulator, the thickness of the quantum well layer can be increased to 60 °, which is about 1.5 times that in the case of no strain, while maintaining the gain peak wavelength at 1.48 μm. Since the electric field absorption effect is substantially proportional to the fourth power of the well layer thickness, the electric field absorption effect increases by a factor of five. As a result, the driving voltage of the modulator can be reduced to half that of the conventional device, and the chirping at the time of modulation can be reduced to about 1/10, and a high performance and highly reliable optical integrated device can be realized extremely easily.

FIG. 8 shows a quantum well layer 14 having a tensile strain of -1.5% and -1.0%, respectively, in the optical modulator and the distributed feedback type laser unit in the first embodiment. , And further embedded structure,
5 shows an element structure of an embodiment in which a current confinement structure is introduced by a known method. In this case, the oscillation light is in the TM mode, and a light hole band is involved in laser emission and light absorption instead of the conventional heavy hole band. Therefore, the stability of the oscillation wavelength of the laser, the modulation efficiency of the modulator, and the high speed can be greatly improved.

Embodiment 3 In the optical integrated device shown in FIG. 9, the gain peak wavelengths in two regions are set to 1.50 μm, respectively, in the same manner as in Embodiment 1.
At the same time as setting to 1.55 μm, the lattice strain of the quantum well structure is set to −1.0% and 0.5%, respectively. After each semiconductor layer is formed in this manner, the upper isolation electrode 16,
The lower electrode 17 is formed by a normal vapor deposition method or the like to obtain a semiconductor optical integrated device. By using this structure as a TE and TM mode optical amplifier, respectively, and independently controlling the amplification factors of the TE and TM modes by current injection, a polarization independent optical amplifier can be realized very easily. FIG. 9 further shows an embedded structure,
5 shows an element structure of an embodiment in which a current confinement structure is introduced by a known method. Thereby, the polarization independence of the optical amplifier can be completely removed. Further, the TE and TM mode filters can be configured by independently controlling the amplification factor and absorption coefficient of the TE or TM mode by current injection or voltage application.

Embodiment 4 In FIG. 9, the region (growth region width) where the semiconductor substrate is exposed on the n-InP substrate 8 is the region where the diffraction grating 9 is formed and the region where the diffraction grating 9 is not formed in the direction of the optical waveguide. forming different SiO _2, SiN _X, the patterning mask 10 made of an insulating material such as a-Si width. Next, an In ₀ in the patterning on the _{substrate. 85 Ga 0. 15 As 0} . 33 P 0. 67 four yuan waveguide layer _{11, In x Ga 1-x} As ternary quantum well layer 12 and an In _{0. 85} Ga _{0. 15 As 0. 33 P} 0. 67 consists of four yuan quantum barrier layer 13 multiple quantum well layer 14, and successively a p-InP cladding layer 15 is crystal grown by metalorganic vapor phase epitaxy. At this time, the composition of the ternary and quaternary crystals grown in the aperture region changes according to the mask width of the patterning mask as shown in FIG. From FIG. 4, by setting the mask widths of the two regions to 30 μm and 70 μm, respectively, the gain peak wavelengths are set to 1.25 μm and 1.55 μm, respectively.
Set to 1%. After forming each semiconductor layer in this manner, the upper electrode 16 and the lower electrode 17 are formed by a normal vapor deposition method or the like to obtain a semiconductor optical integrated device. By using this structure as the distributed reflector 18 and the active region 19, a distributed reflection laser can be realized. FIG. 10 shows an element structure of an embodiment in which a buried structure and a current confinement structure are further introduced by a known method. In this case, the active layer 19 having a compressive strain
Reflector 1 having tensile strain for TE light generated by
8 is almost lossless, so that the oscillation threshold of the laser can be reduced and the spectral line width can be reduced. In this embodiment, the active region is constituted by a compression strain quantum well, and the distributed reflector 18 is constituted by a tensile strain quantum well.

Embodiment 5 FIG. 11 shows an embodiment of a cross-type optical switch in which optical amplifiers are integrated by the same method. SiO ₂ , S as shown in FIG.
A quantum well structure 14 having a gain peak wavelength of 1.45 μm and a well layer having a −1% tensile strain is formed on an n-InP substrate 8 having a patterning mask 10 made of an insulator such as iN _x or a-Si. . At this time, in the regions a and c, the gain peak wavelength is 1.50 μm and the well layer has + 0.5% compressive strain. In the region b, the gain peak wavelength is 1.55 μm and the well layer has + 1.0% compressive strain. The width of the mask and the width of the growth region are adjusted so as to be as appropriate. FIG. 11B further shows an embedded structure, a waveguide structure,
5 shows an element structure of an embodiment in which a current confinement structure is introduced by a known method. As described above, by arranging the quantum well structure having both compressive and tensile strains in the plane, the light reflecting portion and the optical amplifying portion respectively have the TE and TM mode polarized light as shown in FIG. It can be controlled independently. According to this embodiment, an optical switch with extremely low loss, high extinction ratio, and complete polarization independence can be realized very easily.

Embodiment 6 FIG. 13 shows a distributed feedback laser and optical modulator integrated device 21 of Embodiment 1 or 2 on a submount 20 and a spherical fiber 23 on a light axis thereof via a spherical lens 22. An optical communication transmission module 25 which is fixed and further incorporates a modulation drive circuit 24. By using this module, a high-speed optical signal with high fiber output and low chirping can be easily generated.

Embodiment 7 FIG. 14 shows a polarization-independent optical amplifier 26 of Embodiment 3 mounted on a submount 20 and two front-end fibers 23 fixed on its optical axis via a spherical lens 22. This is an optical communication relay module 28 incorporating a drive circuit 27. By using this module, a completely polarization-independent optical repeater module can be realized very easily by controlling the gains of the TE and TM modes independently.

Embodiment 8 FIG. 15 shows a trunk optical communication system using the transmission module 25 of Embodiment 5. The transmitting device 29 includes a transmitting module 25 and a driving system 3 for driving the module 25.
0. The optical signal from the module 25 passes through the fiber 31 and is detected by the light receiving unit 33 in the receiving device 32. According to the optical communication system according to the present embodiment, 100 km
The above-described relayless optical transmission can be easily realized. This is based on the fact that the signal degradation due to the dispersion of the fiber 31 is also significantly reduced as a result of the significantly reduced chirping.

[0022]

According to the semiconductor optical integrated device of the present invention,
By integrating a plurality of quantum well structures having different quantum well layer thicknesses and different strain amounts (degree of lattice mismatch, compressive strain / tensile strain), the performance of the semiconductor optical device can be greatly improved. Further, according to the method for manufacturing a semiconductor optical integrated device of the present invention, it is possible to realize a quantum well structure in which a plurality of quantum well layer thicknesses and strain amounts (lattice mismatch, compressive strain / tensile strain) are different in a substrate plane. Further, by combining the above-mentioned distortion amounts, optical waveguides having different polarization plane dependencies, which have not existed in the past, can be integrated, and an integrated optical element capable of arbitrarily controlling the plane of polarization of operating light and a suitable manufacturing method thereof are provided. be able to.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a conventional technique.

FIG. 2 is a diagram for explaining the operation of the present invention.

FIG. 3 is a diagram for explaining the operation of the present invention.

FIG. 4 is a diagram for explaining the operation of the present invention.

FIG. 5 is a diagram for explaining the operation of the present invention.

FIG. 6 is a diagram for explaining an embodiment of the present invention.

FIG. 7 is a diagram for explaining an embodiment of the present invention.

FIG. 8 is a diagram for explaining an embodiment of the present invention.

FIG. 9 is a diagram for explaining an embodiment of the present invention.

FIG. 10 is a diagram for explaining an embodiment of the present invention.

FIG. 11 is a diagram for explaining an embodiment of the present invention.

FIG. 12 is a diagram for explaining an embodiment of the present invention.

FIG. 13 is a diagram illustrating an example of the present invention.

FIG. 14 is a diagram for explaining an example of the present invention.

FIG. 15 is a diagram illustrating an example of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Insulating film patterning mask, 2 ... Semiconductor substrate, 3 ...
Quantum well structure, 4 ... optical waveguide layer, 5 ... quantum well layer, 6 ...
Quantum barrier layer, 7 cladding layer, 8 n-InP substrate, 9
... Diffraction grating, 10 ... Patterning mask, 11 ... InG
aAsP waveguide layer, 12: InGaAs ternary quantum well layer, 13: InGaAsP quantum barrier layer, 14: multiple quantum well structure, 15: p-InP cladding layer, 16: upper electrode, 17: lower electrode, 18: distributed reflection 19, active layer, 20: submount, 21: optical modulator integrated element, 2
2 ... sphere lens, 23 ... sphere fiber, 24 ... modulation driving circuit, 25 ... transmission module for optical communication, 26 ... polarization independent optical amplifier, 27 ... module driving system, 28 ... relay module for optical communication, 29 ... Transmission device, 30: transmission module drive system, 31: optical fiber, 32: reception device, 33: light receiving unit.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Makoto Suzuki 1-280 Higashi Koikekubo, Kokubunji-shi, Tokyo Inside the Central Research Laboratory of Hitachi, Ltd. (72) Inventor Makoto Takahashi 1-280 Higashi Koikekubo, Kokubunji-shi, Tokyo Hitachi Central Research Laboratory (72) Inventor Kazuhisa Uomi 1-280 Higashi Koikekubo, Kokubunji-shi, Tokyo Hitachi Central Research Laboratory, Inc. 72) Inventor Atsushi Takai 1-280 Higashi Koigakubo, Kokubunji-shi, Tokyo Inside the Central Research Laboratory, Hitachi, Ltd. (56) References JP-A-3-174790 (JP, A) JP-A-1-257386 (JP, A) JP-A-5-29602 (JP, A) JP-A-2-62090 (JP, A) JP 4-303982 (JP, A) JP-A-4-233783 (JP, A) JP-A-4-100291 (JP, A) JP-A-3-289631 (JP, A) Applied Physics Letters, 59 [4] , P. 443-445 Journal of Crystal Growth, 107, p. 151-155 Journal of Crystal Growth, 107, p. 147-150 Applied Physics Letters, 51 [14], p. 1091-1093 Electronics Letters, 28 [2], p. 153-154 Electronics Letters, 27 [23], p. 2138-2140 (58) Fields investigated (Int. Cl. ⁷ , DB name) H01S 5/00-5/50 G02B 6/122 H01L 27/15 JICST file (JOIS)

Claims (8)

(57) [Claims] 1. A semiconductor optical integrated device having, in addition to a semiconductor laser having a first optical waveguide layer made of a compound semiconductor, a semiconductor optical modulator having a second optical waveguide layer made of a compound semiconductor on the same semiconductor substrate surface. in the manufacturing method for the device, said first plurality of crystal growth layer of the optical waveguide layer at least one has a first lattice constant different from the substrate, a plurality of crystal growth for forming the second optical waveguide layer at least one layer having a second lattice constant different from the substrate, and the first
The lattice constants between said second lattice constant is different values,
The formation of the first and the core layer of the second optical waveguide layer once
All SANYO performed by selective growth, the first optical waveguide layer
Between the region where the second optical waveguide layer is to be formed and the region where the second optical waveguide layer is to be formed.
In each case, the mask width on the substrate surface (the mask width
The width is 0 or more. ) And growth area width
By this, the first optical waveguide layer and the second optical waveguide layer
The method of manufacturing a semiconductor optical integrated element characterized that you adjust the band gap and the strain amount in respectively. 2. The method for manufacturing a semiconductor optical integrated device according to claim 1, wherein said crystal growth layer is formed by metal organic chemical vapor deposition. 3. In addition to a first semiconductor optical amplifier for amplifying TE polarized light having a first optical waveguide layer made of a compound semiconductor,
In a method for manufacturing a semiconductor optical integrated device having a second semiconductor optical amplifier for amplifying TM polarized light having a second optical waveguide layer made of a compound semiconductor on the same semiconductor substrate surface, the first optical waveguide layer is formed. At least one of the plurality of crystal growth layers has a first lattice constant different from the substrate, and at least one of the plurality of crystal growth layers constituting the second optical waveguide layer has a second lattice constant different from the substrate. And the first
And the second lattice constant are different values,
The formation of the core layers of the first and second optical waveguide layers is performed by one selective growth, and the area where the first optical waveguide layer is formed and the area where the second optical waveguide layer is formed In each of the above, the first optical waveguide layer and the second optical waveguide layer are respectively adjusted by adjusting both the mask width on the substrate surface (the mask width is 0 or more) and the growth region width. A method of manufacturing a semiconductor optical integrated device, wherein a band gap and a distortion amount are adjusted. 4. The method according to claim 1, wherein said crystal growth layer is formed by metal organic chemical vapor deposition. 5. A semiconductor optical integrated device having a semiconductor laser having a first optical waveguide layer made of a compound semiconductor and a semiconductor optical modulator having a second optical waveguide layer made of a compound semiconductor on the same semiconductor substrate surface. , At least one of the plurality of crystal growth layers constituting the first optical waveguide layer has a first lattice constant different from that of the substrate, and at least one of the plurality of crystal growth layers constituting the second optical waveguide layer One has a second lattice constant different from that of the substrate, and the first lattice constant and the second lattice constant are different values, and the first optical waveguide layer and the second optical waveguide layer Are smoothly coupled by one selective growth, and the mask width on the substrate surface (provided that the region where the first optical waveguide layer is formed and the region where the second optical waveguide layer is formed) The mask width is 0 or more.) A semiconductor optical integrated device, wherein a band gap and an amount of distortion are adjusted in each of the first optical waveguide layer and the second optical waveguide layer by adjusting both of the region widths. 6. The semiconductor optical integrated device according to claim 5, a waveguide means for guiding output light from the semiconductor optical integrated device to the outside, and the semiconductor optical integrated device provided in the waveguide means. An optical communication module, comprising: condensing means for condensing the output light from the device; and driving means for driving the semiconductor optical integrated device. 7. A transmitter having the semiconductor optical integrated device according to claim 5, a waveguide for guiding output light from the transmitter to the outside, and receiving output light from the waveguide. Optical communication system having a receiving means for performing communication. 8. A first semiconductor optical amplifier for amplifying TE polarized light having a first optical waveguide layer made of a compound semiconductor and a second semiconductor optical amplifier for amplifying TM polarized light having a second optical waveguide layer made of a compound semiconductor. A semiconductor optical integrated device having two semiconductor optical amplifiers on the same semiconductor substrate surface, wherein at least one of a plurality of crystal growth layers constituting the first optical waveguide layer has a first lattice constant different from that of the substrate; At least one of the plurality of crystal growth layers constituting the second optical waveguide layer has a second lattice constant different from that of the substrate, and the first lattice constant and the second lattice constant have different values. The first optical waveguide layer and the second optical waveguide layer are smoothly coupled by one selective growth, and the region where the first optical waveguide layer is formed and the second optical waveguide layer are connected. On the substrate surface in each of the regions where the layers are to be formed By adjusting both the mask width (where the mask width is 0 or more) and the growth region width, the band gap, the amount of distortion, and the like in each of the first optical waveguide layer and the second optical waveguide layer are adjusted. The semiconductor optical integrated device, wherein is adjusted.